Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Chemistry  (6)
  • Column liquid chromatography  (4)
  • Polymer and Materials Science  (3)
  • 1
    Digitale Medien
    Digitale Medien
    Determination of pheophytinatonickel(II) by reversed-phase highperformance liquid chromatography (1988)
    Springer
    Chromatographia 25 (1988), S. 319-323 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Pheophytinatonicke(II) ; Chlorophyll ; Pheophytin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary HPLC determination of pheophytinatonicke(II) (Pheo-Ni) prepared by the replacement of magnesium(II) in chlorophyll with nicke(II) is described. The good separation of PheoNi was obtained by using chemically bonded C18 as the stationary phase and acetone-methanol (50∶50, vol/vol) as the mobile phase. Conventional spectrophotometric method was also used for the determination of PheoNi. For the synthetic samples prepared by mixing (pheophytinato a) nicke(II) [(Pheo-a) Ni] and (pheophytinato b) nicke(II) [(Pheo-b) Ni], analytical values obtained by the spectrophotometric method were very high compared to those obtained by HPLC. In the proposed HPLC method, (Pheo-a) Ni and (Pheo-b). Ni could be determined in the concentration range of 0.028–30μg/ml and 0.038–30μg/ml with relative standard deviations (n=10) of 3.1% and 0.8%, respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02324707
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Preparation and determination of manganese(III) chlorophylls by reversed-phase high performance liquid chromatography (1992)
    Springer
    Chromatographia 33 (1992), S. 567-570 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Chlorophylls ; Manganese(III) chlorophylls
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Manganese chlorophylls have been synthesized by refluxing a mixture of pheophytins dissolved in acetone and manganese(II) acetate anhydride dissolved in glacial acetic acid. A good separation of manganese(III) chlorophylls has been attained by RP-HPLC using chemically bonded C18 silica as a stationary phase and methanol with 3% acetic acid as a mobile phase. An accurate and rapid HPLC method is described for the simultaneous determination of manganese(III) chlorophyll-a [Mn(III)-chl-a] and manganese(III) chlorophyll-b [Mn(III)-chl-b]. Tailing arising from dissociation of acetate ions is improved by addition of sodium acetate (5×10−3 M) to the mobile phase (acetone: methanol=90∶10, vol/vol). The analytical values obtained by the HPLC method are very close to the calculated contents in all samples, but those obtained by spectrophotometry are high because of the interferences from overlapping of absorption bands. In the proposed HPLC method the calibration graphs of Mn(III)-chl-a and Mn(III)-chl-b are linear in the concentration range 0–20 μg cm−3 with relative standard deviations (n=10) of 3.46% and 4.54%, respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02262249
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Preparation and separation of metallobacteriochlorophylla by reversed-phase high-performance liquid chromatography (1996)
    Springer
    Chromatographia 43 (1996), S. 361-364 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Bacteriochlorophylla ; Copper(II) bacteriochlorophylla ; Zinc(II) bacteriochlorophylla
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Semi-preparative high-performance liquid chromatography has been used for the preparation of copper(II) bacteriochlorophylla [Cu(II)-BChl-a] and zinc(II) bacteriochlorophylla [Zn(II)-BChl-a]. Both compounds are separated on a reversed-phase Inertsil ODS-2 column using a mobile phase of acetone-methanol (25∶75, v/v). The fractionated metallobacteriochlorophylls (M-Bchl-a) are identified by fast atom bombardment mass spectrometry. The spectroscopic parameters such as the wavelength of absorption maxima and the molar extinction coefficients are determined using pure M-Bchl-a obtained by preparative HPLC. The HPLC method proposed here has been demonstrated to be useful for the purification and determination of components of M-Bchl-a.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02271011
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Transport of a gas through asymmetric polysulfone membranes with deposited plasma-polymerized thin layer (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 41 (1990), S. 2427-2436 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: A plasma-polymerized thin layer was deposited on the top surface of the skin layer of the asymmetric polysulfone (PSF) membrane to plug ultrafine pores passing through it. Trifluoromethane was used as the monomer gas of plasma polymerization. The steady-state permeation rates for oxygen and nitrogen through the asymmetric PSF membranes with the plasma modification were measured to evaluate the permselectivity and permeability. If ultrafine pores passing through the asymmetric membrane can be plugged by the plasma-polymerized thin layer, the separation factor of oxygen relative to nitrogen can be increased with the permeation rate coefficient of oxygen still kept large. This condition was met when the vaporization time of the cast solution during the preparation of an asymmetric membrane ranged from 10 to 120 s and the plasma polymerization time ranged from 15 to 30 min.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1990.070410942
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Effect of organic solvents on the activity of glucoamylase (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 28 (1986), S. 1172-1177 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Hydrolyses of maltose, maltotriose, and soluble starch catalyzed by glucoamylase (Asp. Niger) were carried out in the aqueous solutions of methanol, ethanol, ethylene glycol, and 1,4-dioxane at 40°C and at the optimum pH in the respective solutions. By the kinetic analysis based on the subsite model, it was shown that the intrinsic rate constant, Kint, was electrostatically affected by the dielectric constant of the hydroorganic solutions. The affinity of the third subsite, A3, which affects the apparent rate constant, K0, was correlated with the ×Gtr's of maltose and amino acid side chains.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260280807
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Viscosity of concentrated styrene solutions of polystyrene (1968)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 12 (1968), S. 9-11 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Viscosities of concentrated solutions of polystyrene of different intrinsic viscosities were measured at varying polymer concentration and temperature. By modifying Martin's equation, an empirical equation correlating the viscosity of the solution as a function of the polymer concentration, the intrinsic viscosity of the polymer, and temperature was obtained.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1968.070120102
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Korrelation zwischen Mössbauer-Isomerieverschiebungen und ESCA-Bindungsenergien (1981)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 483 (1981), S. 75-85 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Correlation between Mössbauer Isomer Shifts and ESCA Binding EnergiesThe correlation between core-electron binding energies and Mössbauer isomer shifts is investigated and discussed for low-spin pentacyanoferrates(II), high-spin iron(III) compounds and high-spin iron(II) halides. The Fe2p3/2 binding energies of the investigated pentacyano ferrates(II) increase with decreasing isomer shifts as a consequence of the increasing π acid strengths of the sixth ligands. In contrast, the electron binding energies in high spin iron(III) compounds and iron(II) halides increase with increasing isomer shifts. This correlation is caused by the σ donor properties and the electronegativity of the ligands.
    Notizen: Der Zusammenhang zwischen core-Elektronen-Bindungsenergien und Mössbauer-Isomerieverschiebungen wird für low-spin-Pentacyanoferrate(II), high-spin-Eisen(III)-Verbindungen und high-spin-Eisen(II)-halogenide untersucht und diskutiert. Die Fe2p3/2-Bindungsenergien der untersuchten Pentacyanoferrate(II) nehmen mit Kleiner werdenden Isomerieverschiebungen als Folge zunehmender π-Säurestärken der sechsten Liganden zu. Im Gegensatz dazu wachsen die Bindungsenergien der high-spin-Eisen(III)-Verbindungen und Eisen(II)-Halogenide mit zunehmender Isomerieverschiebung. Ursache sind die σ-Donoreigenschaften und die Elektronegativität der Liganden.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19814831210
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Mössbauer and X-ray photoelectron spectroscopic studies of prussian blue and its related compounds (1977)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 430 (1977), S. 241-249 
    Details
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Mössbauer- und Röntgen-Photoelektronenspektroskopische Untersuchungen an Berlinerblau und verwandten VerbindungenDie 57Fe-Mössbauer-Spektren der drei isomorphen Verbindungen des Typs Fe4[MB(CN)6]3 · xH2O (MB = Fe, Ru bzw. Os) wurden im Temperaturbereich von -178 bis 25°C gemessen. Die Spektren der Ruthenium- und Osmium-Verbindungen sind sehr ähnlich dem des angereicherten 57Fe4[Fe(CN)6]3 · xH2O. Die Temperaturabhängigkeit der Isomerieverschiebung und der Quadrupolaufspaltung wird interpretiert als Ausdruck der Gitterdynamik. Die Röntgen-Photoelektronenspektren unterstützen die Schlußfolgerungen aus den Mössbauer-Untersuchungen.
    Notizen: The 57Fe Mössbauer spectra of three isomorphous compounds of the type Fe4[MB(CN)6]3 · xH2O, where MB is Fe, Ru or Os, have been measured in the temperature range between -178 and 25°C. The spectral pattern of the ruthenium and osmium compounds is very similar to that of selectively enriched 57Fe4[Fe(CN)6]3 · xH2O. The temperature dependence of the isomer shift and quadrupole splitting is interpreted in terms of lattice dynamics. The X-ray photoelectron spectra also support the conclusions drawn from the Mössbauer study.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/zaac.19774300123
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Separation and determination of nitrite ion by affinity chromatography with cyano(pheophytinato a)cobalt(III) charged column (1989)
    Springer
    Chromatographia 27 (1989), S. 461-464 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Chlorophyll-bonded stationary phase ; Cyano(pheophytinato a)cobalt(III) ; Pheophytin a
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The separation and determination of the nitrite ion by affinity chromatography is described. The good separation of the nitrite ion was obtained by using cyano-(pheophytinato a)cobalt(III) bonded octadecylsilica as the stationary phase and water of pH 4.3 adjusted by acetic acid as the mobile phase. Conventional ion chromatograph was also used for the analysis of the nitrite ion. For the synthetic samples prepared by mixing the nitrite and nitrate ions, analytical values obtained by affinity chromatography were in agreement with calculated values and close to the analytical values obtained by ion chromatography. In the proposed affinity chromatography, the nitrite and nitrate ions could be determined in the concentration range of 0.15–1.0ppm and 0.1–1.0ppm with relative standard deviations (n=10) of 5.3% and 4.7%, respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02319564
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Polymerization in submonolayers of styrene monomer adsorbed from its vapor phase (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 26 (1988), S. 1519-1527 
    Details
    ISSN: 0887-6266
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: The surface coverage of porous glass (PD = 500 Å) by styrene adsorbed from its vapor (0.1-6 torr) was studied in a vacuum electrobalance. The adsorption isotherm of the monomer was analyzed by the BET method, and a full monolayer coverage was found to form at a relative pressure of 0.11, weighing 6 mg per gram of glass. Polymerization in submonolayers of adsorbed styrene was initiated by thermal decomposition of predeposited BPO and found to continue until all initiator decomposed, sample cooled, or vapor removed, hence allowing a controlled film thickness. The films were extracted in THF and analyzed by computerized GPC. Molecular weights were in the range 18000-69000. These were related to the rates of polymerization by the usual statistical correlations.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/polb.1988.090260713
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...